Energy saving strategies for city trams: a case study

Nowadays, more than half of the world’s population live in cities. The urban mass transportation represents a big issue, and its design and operation must cope with environmental concerns. Trams are certainly one of the least energy consuming and most sustainable mass transit systems a city can operate, especially with reference to the newly installed networks. In any case, existing networks have margins of improvement and can benefit from the adoption of appropriate energy saving strategies. In this paper, a mathematical model of a tram run has been developed and validated with real data. Then, a study has been performed, based on this model, to analyze the influence of different operation strategies on the energy consumption. The longest tram route of the city of Rome (Italy) has been taken as a reference. The advantages of traffic light priority, dedicated lane, and coasting techniques have been quantified in terms of energy savings with reference to the case study. The developed model is versatile and enough accurate to perform other sensitivity studies. Moreover, it can constitute the core of an automated onboard management and control system.